Need: Arcee's left arm

My FE Arcee's left arm came defective and won't stay attached to the ball joint. It sits on there, loosely and not snapped in tightly, but any subtle movement knocks it off again. I have to take her arm off, pose/transform it seperately, and then reattach it last.

I am hoping someone might have a spare that I could snag, leftover from a custom job or something, maybe. I realize its a long shot due to her scarcity, but I'd appreciate any help in the matter.

I'd also be willing to accept advice on how to possibly fix it, if anyone else has come across a similar problem.